Hypodermic syringe



June 21, 1949. A. E; SMITH 2,473,734

HYPODERMIC SYRINGE Filed May 31, 1947 III/7;

1 jl@ Z4 Z6 z5 393 o i! 42313 4g I0 A? fj i y z6- '7 z l! INVENTOR.y AKW/ME SM/ TH BY Patented June Z1, 1949 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to improvements in disposable hypodermic syringes.

The general object of the invention is to provide an improved single-use hypodermic syringe whereby medicinal compounds such as penicillinoilwax may be administered in an efficient manner.

A more specific object of the invention is to provide an improved ampule stopper particularly adapted for use as an element in a disposable syringe.

A further object of the invention is to provide a novel plunger for ampule type syringes.

Another object of the invention is to provide a novel closure for the ampule of a disposable syringes.

Another object of the invention is to provide a disposable syringe including a front ampule closure having novel finger engaging means thereon.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, wherein Fig. 1 is a central sectional View of a disposable syringe showing my invention;

Fig. 2 is a View similar to Fig. 1, showing the syringe prepared for use;

Fig. 3 is a yiew similar to Fig. 1, showing the syringe after the contents have been discharged;

Fig. 4 is a View similar to Fig. 1, showing a modiiication of my invention;

Fig. 5 is a fragmentary sectional View showing -the manner in which the needle is moved to active position, and

Fig. 6 is a fragmentary central sectional view showing a modified form of needle construction.

Referring to the drawing by reference characters, i Show my invention as embodied in a disposable syringe which is indicated generally at I0. As shown, the syringe includes an ampule II, a plunger I2, a front member I3 and a stopper I4. The ampule and plunger may be made of glass or plastic material, while the front member I 3, the stopper I 4 and the piston I 5 on the plunger I2 may be made of natural or synthetic rubber.

The ampule II is in the form of a cylinder and the plunger I2 is also cylindrical and includes a reduced portion I6 from which a stem I? extends. The stem I'I has a head I8 thereon. The piston i5 has a recess I9 in one end thereof which communicates with an enlarged recess 29. The recesses i3 and 2B are of a size to receive and grip the portions I? and I8 on the plunger and the end 2I of the piston is rplane and engages the plane face 22 on the reduced portion I6 of the plunger. The forward end of the piston includes a recess 23 which receives the tip of a hypodermic needle (to be later described) when the plunger is at the extreme inward limit of its movement.

The front and back peripheries 2li and 25 of the piston I5 are rounded so that dragging and binding are reduced to a minimum when the piston moves forward in injecting the material and when the piston moves rearwardly in testing as will be later described. The piston also includes peripheral grooves 25 which prevent dragging and binding.

The stopper I4 includes a peripheral flange 30 which engages the end of the ampule il. The outside diameter of the ange is substantially the same as the outside diameter of the ampule II. The forward end of the stopper I4 has a recess 3| while the rear end of the stopper has a reduced recess 32. The recesses 3l and 32 are coaxial and recess 32 is preferably smaller than recess 3l. The recesses 3| and 32 are connected by a thin diaphragm 33 which is adapted to be pierced by a hypodermic needle prior to injection.

The front member I3 is in the nature of a resilient cap and includes a peripheral bead or flange 35 which is adapted to be engaged between the index and second nger of the operator while the injection is being made. The front member includes a forwardly projecting tip 36 which has a curved recess 3l in its forward face. The front 'member includes a rearwardly projecting tip 38 which is normally slightly larger than the recess 3l in which it nts to form a seal. The front member includes a bore 39 which is coaxial with the front member and ampule and in this bore I seat one end portion of a hypodermic needle d@ which extends through the bore and pierces the tip 38 and enters -the recess 3! but normally does not pierce the diaphragm 33.

The needle includes a bulbous shoulder portion 6I which nts in the recess 31 in the tip 35 when the needle is fully seated. The needle projects forwardly at i2 beyond the bulbous portion. The outer end t3 of the needle and the inner end 44 thereof are both sharpened as shown. An elongated cap member 45, preferably vmade of pliable plastic, surrounds the needle and engages the'tip 3S tightly in the position shown in Fig. l. The tip 35 preferably tapers towards the ball tI so that a tight fit may bev had at the cap 45.

The head i8 on the plunger stem is dispose-d near the center of thepiston I5 and thus in pushing and in pulling the piston there is a vsufficient amount of rubber in shear to provide a smooth action. Further, the space 46 between the end 41 of the body of the plunger and the adjacent end 2| of the piston allows the rubber on the piston to move into this space and thus a binding action is avoided. The construction of the piston in a syringe of the present nature is important as the movement of the piston must be under accurate control and if there is-any binding a jar occurs when the parts release and this is a seriouspbjeci0` tion. I have overcome the objections mentioned by the particular manner in which the piston and plunger are made so that a smooth movement is secured throughout the injection.

In use, with the parts in the position shown in .15,

Fig. 1, the operator removes the flexible cap 45 and then by squeezing the caDKaS'fShOWnwinJFig.; 5) engages the bulb 4| and pushes the needle point 44 through the diaphragm 33 so thatthen parts assume the position shown in Fig. 2, in which o condition the needle' communicates fwith' the interior of the-ampule.l Pressure on the outeriend of the plunger IZ'fthen causes the'contents 'of the ampule, such as penicillineoil-wax, to be injected In using many drugs it is essential-that injec- 'tion benot made ina vein'orartery and to determine Whether 'the "needle has been'inserted in-a vein orartery, aft'erth'e'-insertion'ismade, the

withdrawnl and 'if I'the pointof` the' needle* has punctured a bloodfvessel it'will cause blood'tobe aspiratedintofthe ampule; Thus a 'check is'fprovided against improper injection,

In Figs. 4 and-5 I show a'modification-of' my f 35 invention.' In-thefmodiication the'ampule H and thepiston I 5" Vare simi-lar to those previously described.` The frontI member 5l! includes'an integral stopper'portionY 5f. The-front'mem-ber has askirt 52 'which-engages' the exteriorof the 4o ampule Al l'. The front member includesa-shoulder'53`which like theflange 35*may"be engaged bythe fingers 'of the operator'whilezthe injection is being made. The front member 'includes aprojecting tipl 54 whichv Ais tapered'an'd is provided 45 with a. cylindrical' bore 55:'Wh'ich extends therethrough and extends part way l through .the cork portion 5| and-terminatesshort 'of adiaphragm 56. The corkportion includes.: a. recess. 51. A

xible .capAS' surrounds theneedle 42'. 50

Inusethe capfd' is removed. and squeezed vto the positionxshowrrin'Fig. 5so that itengages theeshoulder portion 4 la on the needle so th'atv the needle-'maybe pushed inwardlyrth'rough th'ediaphragm 56 to .the position shown in Figgbtoplace 55 theneedle incommunication with th'e interior Vof the ampule. The plunger I2". and associated parts inthe modication.functiorrth'e same as heretofore 'described In` both' types of my syringesthebores 39 and 6o 55 are of a size to permit the needle to slide freely therein without wobbling and .thus the needl'e.is supported;

In-Fig; 6 I'show a' modificationwherein th'e ampule-I l has a front-member I3" and-ar stop- 65 per I 4 srnilanto Athat previously described. In the-=nrodication the fend 'of the tip-*of ltheffront member is1plane'as1at"50, while-theeneedle A2" has a: generallyfconer-shaped protub'erance 4 l th'ereon.. The protub'erance-'d l 'has a plane rear v70l ent-tirati haveanventedia novet'dsposablefhypo 75 derrnic syringe which is efficient, which is safe in use and which can be economically manuiactured.

Having thus described my invention, I claim:

l. A disposable syringe including an ampule having a plunger slidable thereon, a piston on said plunger, a stopper in said ampule remote from said piston, said stopper having an outwardly,,op ening recess therein and having an interi- ;orly opening recess coaxial 'with theoutward opening recess, a diaphragm separating said recesses, a front member on said ampule, said front member having a nger engaging shoulder thereon; said'front member having an inwardly directed-tipthereon disposed in said outwardly opening recess of said stopper, said front membery,v h'avingra: forwardly projecting tip thereon, said. front member having a bore extending through said forward tip and terminating short of -the inner end of said inwardly extendingmtip, a'needleslidable in said bore and having its inner end extending throughandprojecting beyond sa-id inwardly extending tip,said needle vhaving a protuberancespaced fromV said-tip: andA a `iiexible cap about kthe outer end of vsaidiieedleandseated on' the forwardly projecting tip onrsaid front member.

2;' Ai disposable syringe includingi an" ampule having a plunger slidable therein, Saidplunger 'comprising a cylindrical 'body having a forwardly extending reduced. portion,. a piston.. having a recessY receiving jsaid reduced portion,. azstopper in .said ampule remote fromsaid piston, saidstopper having, an axial recess'and having a dia- A*phragm'closing said 'stopper'recess, a'front membercn said ampule, said front member'having a nger engaging shoulder thereon, said' front member having ya forwardlyand a rearwardly projecting tipthereon, said front member having a .bore extendingthroughv saidA forward tip .and terminating short of .the inner end thereof,` a. needleslidable in said bore and 'having its inner end extending. through. saidrearwardtip, said needle having a protuberance-spaced-from Vsaid forward tip, andsa exible ,capfabout .the outer end of said needle andiseated ion. the forwardly projecting tiponsaidfront member.

3."A disposablesyringeincludihg1 an ampule h'aving a plunger slidable therein, ,saidplunger comprising a cylindrical `b'ody having a. forwardly extending reducedxportioma reduced stem on. said reduced portion, a headon. said stem, va piston having a recess receiving said. stem,and 1heada stopper in. said `ampule remotefrom said piston, said stopper having. an` outwardly, openingrecess therein and vhavingan interiorly openingrecess coaxial .with the outward Iopeningrecessa diaphragm separating said recesses, a front memberlon said ampule, said front member having a iingerY engaging shoulder thereon, said. front member having anA inwardly .directed 'tip thereon disposedin said ,outwardly.openingrecess of said stopper..,saidifrontmember having a forwardly projecting'tip thereon, said front 'member having a'bore extending*through'said forward tipian'd terminating short ofthe. innerend of saidjin- Wardly extendi'nggtip', a needle slidable in said b"ore `and-havingitsinner end extending through and 'projecting- 'beyond said inwardly extending tip; said needle having a'protuberancespaced from said tip, and 'acap seatedjon the forwardly projecting 'tip-'on said i ront member.

4- A' disposable syringe including, an ampule having-'a plungerl slidable '-.thereim Vsaid 'plunger comprising-a cylindrical body having aforwardly' extending reduced portion, a reduced IStem on said reduced portion, a head on said stem, a piston having a recess receiving said stem and head, said piston having a planar rear end and said plunger reduced portion having a planar end face engaging said piston rear end, the rear end of said piston being spaced from the end of the body of the plunger, said piston having a rounded periphery at its front and rear ends, a stopper in said ampule remote from said piston, said stopper having an outwardly opening recess therein and having an interiorly opening recess coaxial with the outwardly opening recess, a diaphragm separating said last mentioned recesses, said stopper having a peripheral ange thereon engaging the end of said ampule, a front member on said ampule, said front member having an outwardly extending, peripheral, nger engaging ange thereon, said front member having an inwardly directed tip thereon disposed in said outwardly opening recess of said stopper, said front member having a tapering forwardly projecting tip thereon, said front member having a bore extending through said forward tip and terminating short of the inner end of said inwardly extending tip, a needle slidable in said bore and having its inner end sharpened and extending through and projecting beyond said inwardly eX- tending tip, said needle having a bulbous portion spaced from said tip, the forward end of said outwardly directed tip having a recess adapted to receive said bulbous portion, and a flexible cap about the outer end of said needle and seated on the forwardly projecting tip on said front member.

ARTHUR E. SM'ITI-I. 

